18819139 has 16 divisors (see below), whose sum is σ = 20736000. Its totient is φ = 17012160.

The previous prime is 18819137. The next prime is 18819167. The reversal of 18819139 is 93191881.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 18819139 - 2¹ = 18819137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18819131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52242 + ... + 52600.

It is an arithmetic number, because the mean of its divisors is an integer number (1296000).

Almost surely, 2^18819139 is an apocalyptic number.

18819139 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

18819139 is a deficient number, since it is larger than the sum of its proper divisors (1916861).

18819139 is a wasteful number, since it uses less digits than its factorization.

18819139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498.

The product of its digits is 15552, while the sum is 40.

The square root of 18819139 is about 4338.1031569109. The cubic root of 18819139 is about 265.9907802032.

The spelling of 18819139 in words is "eighteen million, eight hundred nineteen thousand, one hundred thirty-nine".